CPAP-Therapy (Continuously Positive Airways Pressure-Therapy) affords prevention of sleep related breathing disorders in a physiologically well accepted manner.
By means of respiratory gas supplied at a defined elevated pressure level above ambient pressure a pneumatic splinting of the upper airways may be achieved to effectively prevent potential obstructions in this region—or to afford sufficient Oxygen supply towards the patient in case of temporarily contraction of said upper airways. To achieve high physiological acceptability it is usually envisaged to adjust a low respiratory pressure level affording sufficient pneumatic splinting of the upper airways. However, it has become evident that aforesaid low respiratory pressure level is subject to significant variations. Experiments have been made by using so called AUTO-CPAP devices which for example automatically increase the therapy pressure upon occurrence of snoring sounds, to take these variations in required CPAP-pressure into account. Further CPAP-devices are known for detecting the time related course of the breathing gas flow and analyzing same with respect to features indicative with respect to airway obstructions. In case of such airway obstructions an increase of the therapy-pressure is temporarily administered.
Also there are known Auto-CPAP devices determining the present physiological condition of a patient by means of pressure pulses applied to the respiratory gas supplied via a breathing gas conduit wherein for example on the basis of an impedance detection the present degree of obstruction may be concluded.
From EP 0 612 257 B1 there is known a system for generation of continuously positive respiratory gas pressure, which system changes the pressure level of the gas supplied to the patient in a defined manner, and which analyses changes of the airflow profile that may go along therewith.
With respect to the pressure control concepts applied so far for automatic patient-related adjustment of the breathing gas pressure there exists a problem in that the changes of the respiratory pressure administered thereby are not universally accepted by the respective patients. Further there exists a problem in that the known auto-CPAP systems start to react on significant breathing disorders only.